This study investigated the stress-reducing effect of kabusecha containing of high amounts of theanine, a nutritional component of green tea, on daily high-stress person.

　The subjects were 109 college students and staffs who live in different environments (12 men, 97 women, 19-67 years). Twenty-nine person with high stress (2 men, 27 women, 19-58 years old) were selected by Stress Response Scale-18 (SRS-18), one of the subjective stress evaluation methods. As a single-blind study, a 30-days tea challenge was conducted on them divided into two groups, one is kabusecha containing theanine and the other is barley tea without theanine. The quantitative stress level was assessed with SRS-18 and salivary amylase and blood pressure as objective stress evaluation methods. The quantitative stress levels were assessed with salivary amylase and blood pressure as objective stress evaluation and SRS-18 as subjective evaluation.

　As a result, the salivary amylase level and SRS-18 score decreased significantly in the kabusecha group. It was speculated that kabusecha has an anti-stress effect by suppressing the autonomic nervous system pathway, especially the sympathetic nervous-adrenal medullary axis. Interestingly, blood pressure and SRS-18 score also decreased significantly in the barley tea group. It was considered that barley tea induces a stress-reducing effect by a stress response activation pathway different ,from that of kabusecha.

　These findings suggested that kabusecha has the stress-reducing effect of on someone with high stress in daily life using a combination of subjective and objective measures of stress. In the future, it is expected that as one of the stress coping methods, people could select the tea according to individual stress by clarifying the involvement of various nutritional components in the psychological stress-reducing effect.

Objective: To determine the effects of animal and plant protein intake and protein restriction on phosphorus excretion in healthy young women.

Methods: Healthy young women were divided into four groups: normal (no dietary intervention), animal (animal protein intake), plant (plant protein intake), and low-protein (protein restriction) and subjected to a 3-day dietary intervention. Except in the normal group, vegetable intake was kept to a minimum to eliminate the effects of their constituent minerals. Based on the 3-day dietary records and 24-hour collected urine on day 3, the nutritional value, food group intake, and urinary components were evaluated.

Results: There was no significant difference in the protein and phosphorus intake between the normal, animal, and plant groups. However, urinary phosphorus excretion was significantly lower in the plant and low-protein groups than that in the normal and animal groups; there was no significant difference between the plant and low-protein groups, with similar levels of phosphorus excretion. Magnesium intake and legume intake were significantly higher in the plant group compared to the other groups.

Consideration & Conclusion: We showed that the plant protein diet reduced urinary phosphorus excretion to levels similar to that of the protein-restricted diet, while ensuring a protein intake comparable to that of the animal protein diet. We hypothesize that phytin and magnesium, which are related to the form of phosphorus in foods, are the factors that may explain these findings. Plant proteins may therefore be useful in the prevention of hyperphosphatemia.

　We have developed a novel medium for the culture of lactic acid bacteria using soy whey, instead of using animal-derived materials. Soy whey was prepared by removing soy protein by the treatment with MgCl₂. Various lactic acid bacteria from the culture collection (NBRC) and those isolated from commercially available fermented milk products were cultivated by using the medium based on Mg-soy whey supplemented by yeast extract (YE) and glucose (Glc) as nutrition, designated YE-Glc-Mg-soy whey medium. As a result, the new medium showed almost the same growth rate as that of the MRS medium, which is generally used for culturing lactic acid bacteria. YE-Glc-Mg-soy whey medium was also used for the isolation of lactic acid bacteria, and three Gram-positive strains producing lactic acid were isolated from some citrus fruits. The present study suggested that the YE-Glc-Mg-soy whey medium can be used for the production of fermented foods that are free of allergic substances, and suitable for the people who avoid animal-derived materials because of a religious reason or any other reasons.

　This study investigated the relationship between nutrients and COVID-19 infection in order to provide useful suggestions for infection control in terms of enterobactera. Based on the data taken from a national health and nutrition examination survey, the present study examined the correlation coefficients between each intake of 40 kinds of nutrients and the cumulative number of COVID-19 cases in 12 areas in Japan. The number of COVID-19 cases per 100,000 people were cumulatively counted using three indices; 1) positive cases of PCR test results, 2) inpatients, 3) deaths reported by the Ministry of Health, Labor and Welfare. The results revealed that the intake of carbohydrate and carbohydrate energy ratios had significant and negative correlations with the number of positive PCR test results in the 12 areas. In contrast, the intake of animal proteins, animal fat, monounsaturated fatty acid, fatty energy ratios, and animal protein energy ratios correlated positively and significantly with the number of positive PCR test results. Regarding the number of inpatients, only carbohydrate energy rates had a significant and negative correlation. No other significant and positive or negative correlations were found between the intake of nutrients and the number of inpatients. As for the number of death cases, intake of the carbohydrate energy ratios and vitamin K had significant and negative correlations with it. In contrast, intake of animal protein energy ratios had a significant and positive correlation with it. These findings suggest nutrients seem to prevent or promote COVID-19 infection. Further research is necessary to determine whether these results can be applied to individual participants longitudinally. To do so, the relationship between the immune system and enterobacteria should be examined from the perspective of nutritional physiology.